Boom attachment for fork lift truck



Feb. 17, 1959 .41. c. FowLl-:R y 2,873,873

BOOM ATTACHMENT FOR FORK LIFT TRUCK Filed Nov. 19, 1957 4 Sheets-Sheet 1 .Hirmslm i Mi "UM/Jl mi .l 'l INVENTOR.

' M5555 C. FOWLER Feb. 17, 1959 J. c. FowLl-:R l

BOOM ATTACHMENT FOR FORK LIFT TRUCK 4 Sheets-Sheet 2 Filed Nov. 19, 1957 INVENTOR. c/5555 c. mm f/e Feb. 17, 1959 .1.c. FowLER 2,873,873

BOOM ATTACHMENT FOR FORK LIFT TRUCK Filed Nov. 19, 1957 4 Sheets-Sheet 5 I v INVENTOR. 52 JESSE C. FOM/Lf BY l Feb. 17, 1959 J. c. FowLER 2,873,873

300M ATTACHMENT RoR FORK LIFT TRUCK Fly 5 Filed NOV. 19, 1957 4 Sheets-Sheet 4 ll/ LL// i 33% '-35 l 29 27 z3 20v" III 38 INVENTOR.

L C/[SSE C FOWLER ZZQ/mwm +9@ United States Patent This invention relates to industrial lift trucks, and more particularly to a boom attachment for a fork lift truck, enabling the truck to be used in handlingl packaged loads, such as stacks of lumber and for loading same into freight cars and for removing same from freight cars, or for other similar operations.

A main object of the invention is to provide a novel and improved boom attachment for a fork lift truck, said attachment being simple in construction, being easy to mount on a fork lift truck, and providing a great saving in time and labor in the handling of packaged loads, such as stacks of lumber, or the like.

A further object of the invention is to provide an improved boom attachment for a standard industrial fork lift truck, said attachment involving inexpensive components, being durable in construction, and being safe to use.v

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a fragmentary side elevational view of an improved boom attachment for a fork lift truck, showing the manner in which the attachment is used for handling a bundle of boards.

Figure 2 is a fragmentary top plan view of the boom attachment of Figure 1.

Figure 3 is an enlarged transverse vertical cross sectional view taken on the line 3 3 of Figure 1.

Figure 4 is an enlarged transverse-vertical cross sectional view taken on the line 4 4 of Figure l.

Figure 5 is an enlarged vertical cross sectional detail view taken on the line 5 5 of Figure 3.

Figure 6 is an enlarged vertical cross sectional detail view taken on the line 6 6 of Figure 2.

Referring to the drawings, the improved boom attachment vis designated generally at 11 and comprises a generally rectangular base plate 12 of heavy rigid material, such as sheet steel of substantial thickness. Rigidly secured to the under side of the plate 12 adjacent its side` margins are the respective longitudinally extending channel bars 13 and 14, said channel bars being spaced to receive the respective fork elements 15 and 16 of a standard fork lift truck, designated generally at 17 and shown fragmentarily in dotted View.

A relatively wide channel member 18 is rigidly secured .to the under side of the base plate 12 between the guide channels 13 and 14, as is clearly shown in Figure 3.

Designated generally at 19 is an upstanding bracket structure mounted on the rear portion of the base 12, said bracket structure comprising a pair of vertical side plates 20 and 21 which are welded at their bottom edges to the base plate 12 and which are rigidly connected at their top-edges by a horizontal plate member 22 rigidly welded to said top edges.

Designated at 23 is a vertical swivel bushing which extends through an .aperture 24 formed .in the rear portionof the horizontal plate member 22, the upper por- Pice tion of bushing 23 being provided with a generally rectangular, outwardly extending horizontal flange 26 whose forward portion is fastened to the plate member 22 by a plurality of bolts 27 and whose rear portion projects rearwardly from the bracket structure 19. As shown in Figure 5, the rearwardly projecting portion of flange 26 is adapted to be secured to a transversely extending horizontal frame portion 2S of the lift truck 17, as by bolts 29. Thus, the bracket structure 19 is connected to the lift truck 17 by the fastening bolts 29 connecting flange 26 to the horizontal frame portion 28 of the truck, whereby the plate member 12 is likewise secured to the lift truck in a position wherein the fork elements 15 and 16 of the truck are received in the sleeve-like channel members 13 and 14, as shown in dotted view in Figure 1.

Rigidly secured to the rear portion of plate 12 at one side margin thereof is an upwardly and rearwardly inclined channel bar 30, said channel bar being secured at its bottom end to plate member 12 and being also rigidly secured to the vertical side plate 21 of bracket structure 19. The channel bar 3@ is adapted to be fastened, as a safety measure, in any convenient manner to any conveniently adjacent portion of the lift truck 17 so as to insure that the boom of the attachment will not be released from the lift truck in the` event that the bolts 29 are sheared or broken. For example, the bai` 30 may be lashed by ropes or cables to the horizontal frame element 28.

Designated at 31 is a tubular boom member of substantial diameter and of relatively heavy construction, the boom being supported in a horizontal position over the base plate 12, as will be presently described.

Designated at 32 is a swivel member which is provided with a pair of upwardly and rearwardly extending vertical arms 33, 33 which extend through a notch 34 formed in the end portion of the boom 3'1 and which are pivotally connected to the boom by a transverse pivot bolt 35, whereby the boom is rotatable around the transverse horizontal axis of said pivot bolt. The swivel member 32 is rotatably secured to the top end of the bushing member 23 by a vertical fastening bolt 36 having a head portion 37 received in the enlarged annular seat 33 provided at the lower end of the bushing 23, as is clearly shown in Figure 5. A fastening nut 38 is provided on the top end of the bolt 36, said nut having a washer 39 disposed below the nut and bearing on the member 32, as illustrated in Figure 5. As shown, the vertical fastening bolt 36 is forwardly offset with respect to the transverse pivot bolt 35.

Rigidly secured to the intermediate portion of the boom 31 is a depending vertical support member 40 of box-like construction, the front and rear walls of the boxlike support member depending below the side walls thereof and receiving a pair of rollers 41, 41 therebetween, said rollers being journaled to the lower portions of said front and rear walls by suitable Vjournal pins 42, as shown in Figure 4. Rigidly secured on the transverse forward marginal portion of the plate member 12 is a channel-shaped platform 43, said platform having a c oncave top surface 44 which is depressed at its intermediate portion and which is relatively elevated at its opposite end portions, the rollers 41, 41 supportingly engaging said top surface and being thus urged by gravity toward the depressed intermediate portion of said top surface, as shown in Figure 4. Respective stop blocks .45, 45 are secured on the opposite end portions of top surface 44 of platform 43, as shown in Figure 2, said stop blocks 45 being in the path of arcuate movement of the rollers 41, 41 and limiting the arcuate swing of the boom 31 to positions between the stop blocks 45, 45, namely, to a range of movement substantially as illustrated in Figure 2, wherein the boom is shown in full line view at the limit of its clockwise movement, as viewed in Figure 2, and wherein the boom is shown in dotted view substantially adjacent to the limit of its counter-clockwise movement.

Designated at 47 is a horizontal plate member of substantial thickness which is rigidly secured in and which projects forwardly from the forward end of the boom 31. Thus, as shown in Figure 6,'the plate member 47 projects forwardly a substantial distance from the end of the boom 31 and is provided with an aperture 48 in its forwardly projecting portion. Secured on the forward portion of the plate member 47 around the aperture 48 is an annular bearing collar 49 through which extends a vertical pivot stud 50, said pivot stud being provided with the circular head 51 rotatably and supportingly engaged on the bearing collar 49, as shown in Figure 6. The lower end portion of the stud 50 is rigidly secured to the intermediate portion of a horizontal, elongated plate member 52 of substantial thickness, as shown in Figure 6, said plate member being provided at its respective end portions with pairs of spaced upstanding studs 53 arranged in rows, as illustrated in Figure 2, the rows being parallel and being inclined with respect to the transverse ends 54 of the plate member 52. As shown in Figure 2, each end portion of plate member 52 is provided with a pair of rows of spaced studs 53, said studs being adapted to be engaged by the respective end loops 55, 55 of a sling member 56 made of steel cable or other suitable flexible material, the slings 56, 56 being supportingly engaged around a bundle 57 of wood boards or other material being handled by the boom attachment.

As will be readily apparent, the sling members 56, 56 may be engaged around the bundle of material 57 and the loops 55, 55 at the ends of each sling member may be engaged with selected studs 53, whereby the slings may be adjusted in accordance with the transverse cross sectional area of the bundle 57.

In operation, the attachment is secured to the lift truck in the manner above described, namely, with the fork elements 1S and 16 of the lift truck engaged in the sleeve members 13 and 14 and with the ange 26 of bushing member 23 fastened to the transversely extending horizontal plate element 28 of the lift truck by the bolts 29. The lift truck may be then moved to a position wherein the bearing plate 52 at the forward end of the boom overlies the bundle 57 to be transported, whereby the slings S6, 56 may be engaged around the bundle and may be secured to the upstanding studs 53, as above described. The bundle 57 may then be elevated by the lift truck and may be transported to a freight car or other intended destination, the bundle being rotatable relative to the forward end of the boom, so that it may be suitably oriented for entry into the freight car or into any other enclosure where it is to be deposited. When the bundle is inside the enclosure it may be rotated-to the desired position thereof within the enclosure, and may be then lowered torest on the floor of the enclosure, after which the sling members 56, 56 may be detached from the plate member 52, allowing the boom to be withdrawn by the lift truck for handling the next bundle of material.

Since the boom 33 is rotatable around the vertical axis defined by the swivel connecting bolt 38 and may travel over the platform member 43, the bundle may not only be rotated around the forward end of the boom 33 but may be also moved with respect to the rear pivotal connection of the boom.

,Since the boom is rotatable upwardly around the rear transverse pivot pin 35, the load may be lowered onto the oor of the freight car or other enclosure intended to receive same without damage to the boom, since the boom is free to rotate upwardly around its rear pivotal Connection at the pivot bolt 3S as the load engages the floor responsive to the lowering of the fork elements 15 and 16 and in the event that said fork elements are lowered beyond the point where the load engages said floor. As will be readily understood, this may occur when the fork elements 15 and 16 are lowered relative to the frame of the lift truck 17 when a load attached to the boom is being deposited in a freight car or on any other support intended to receive same.

The boom attachment above described is especially useful in handling packages or bundles of lumber or other similar material, whereby relatively large quantities of lumber may be handled as unitary packages, greatly reducing the amount of time and labor required in the handling of such material.

While a specific embodiment of an improved boom attachment for a fork lift truck has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. A boom attachment for a fork lift truck comprising a base having sleeve-like portions adapted to receive the fork elements of a fork lift truck, upstanding bracket means on the rear end portion of said base, a vertical swivel bushing on said bracket means, means for securing the upper end portion of said bracket means to the frame of the lift truck, a horizontal boom, a swivel bracket, means pivotally connecting the rear end portion of said boom to said swivel bracket for rotation on a transverse horizontal axis, a vertical swivel bolt extending through said swivel bracket and swivel bushing and connecting said swivel bracket to said bushing for rotation around a vertical axis, an upwardly concave, transversely extending support platform on the forward end portion of said base, a depending vertical support member rigidly secured to said boom over said platform, roller means journaled to the vertical support member and supportingly engaging said platform, and a load carrier member rotatably connected to the forward end portion of said boom.

2. A boom attachment for a fork lift truck comprising a base having sleeve-like portions adapted to receive the fork elements of a fork lift truck, upstanding bracket means on the rear end portion of said base, a vertical swivel bushing on said bracket means, means for securing the upper end portion of said bracket means to the frame of the lift truck, a horizontal boom, a swivel bracket, means pivotally connecting the rear end portion of said boom to said swivel bracket for rotation on a transverse horizontal axis, a vertical swivel bolt extending through said swivel bracket and swivel bushing and connecting said swivel bracket to said bushing for rotation around a vertical axis, an upwardly concave, transversely extending support platform on the forward end portion of said base, a depending vertical support member rigidly secured to said boom over said platform, roller means journaled to the vertical support member supportingly engaging said platform, an elongated plate member disposed beneath the forward end of said boom, and vertical pivot shaft means rotatably connecting the forward end of the boom to a portion of said plate member located in the transverse median plane of said plate member.

3. A boom attachment for a fork lift truck comprising a base having sleeve-like portions adapted to receive the fork elements of a fork lift truck, upstanding bracket means on the rear end portion of said base, a vertical swivel bushing on said bracket means, means for securing the upper end portion of said bracket means to the frame of the lift truck, a horizontal boom, a swivel bracket, means pivotally connecting the rear end portion of said boom to said swivel bracket for rotation on a trans- Verse horizontal aXiS, a vertical swivel bolt extending through said swivel bushing and swivel bracket and connecting said swivel bracket to said bushing for rotation around a vertical axis, an upwardly concave, transversely extending support platform on the forward end portion of said base, a depending vertical support member rigidly secured to said boom over said platform, roller means journaled to the vertical support member and supportingly engaging said platform, a horizontal plate element rigidly lsecured to the forward end of the boom and projecting forwardly therefrom,V an elongated support plate disposed subjacent the forward end of said plate element, and an upstanding headed pivot stud rigidly secured to a portion of said support plate located in the transverse median plane of said plate member and extending rotatably and supportingly through said plate element.

4. A boom attachment for a fork lift truck comprising a base having sleeve-like portions adapted to receive the fork elements of a fork lift truck, upstanding bracket means on the rear end portions of said base, a vertical swivel bushing on said bracket means, means for securing the upper end portion of said bracket means to the frame of the lift truck, a horizontal boom, a swivel bracket, means pivotally connecting the rear end portion of said boom to said swivel bracket for rotation on a transverse horizontal axis, a vertical swivel bolt extending through said swivel bushing and swivel bracket and connecting said swivel bracket to said bushing for rotation around a vertical axis, a transversely extending support platform on the forward end portion of said base, said platform having a concave top surface which is depressed along its transversal axis at its intermediate portransversal axis, a depending vertical support member rigidly secured to said boom over said platform, roller means journaled to the vertical support member and supportingly engaging said platform, a horizontally extending elongated load-carrying member disposed beneath the forward end portion of said boom, and means swivelly connecting a portion of said load-carrying member located in the transverse median plane of said load-carrying member to said forward end portion of the boom for rotation around a vertical axis.

5. A boom attachment for a fork lift truck comprising a base, means on the base formed and arranged to slidably receive the fork elements of a fork 'lift truck, upstanding bracket means on the rear end portion of said base, a horizontal boom, means rotatably securing the rear end of the boom to said bracket means for rotation around vertical and transverse horizontal axes, depending support means rigidly connected to the intermediate portion of the boom, an upwardly concave transversely extending supporting element on said base located beneath and supportingly receiving said depending support means, and a load supporting member rotatably connected to the forward end portion of said boom.

References Cited in the le of this patent UNITED STATES PATENTS 1,389,021 Vest Aug. 30, 1921 2,387,744 Clapp Oct. 30, 1945 2,571,858 Garland Oct. 16, 1951 2,803,363 Hutchinson Aug. 20, 1957 

